Individuals with cervical spinal cord injury often cite loss of hand and arm function as the most devastating consequence of their injury, yet there are few interventions available to improve hand function in individuals with chronic tetraplegia, making this an unmet need. The proposed studies target this need by examining rehabilitation interventions designed to improve skilled hand/arm use in individuals with chronic tetraplegia. Evidence suggests that while deficits of hand function in individuals with tetraplegia are primarily due to damage to descending corticospinal connections, secondarily, learned non-use and decreased cortical excitability likely contribute to ineffective cortical control of the remaining connections to the spinal cord. These secondary changes resemble those that occur after stroke and may be reversible to some extent. Consequently, interventions that are effective for improving hand/arm function after stroke may also be of benefit for individuals with tetraplegia. In individuals with stroke, intensive upper extremity skill training (massed practice) is associated with improved use of the hand. Another intervention, somatosensory stimulation, has been shown to increase cortical excitability in non-disabled individuals and to improve strength in individuals with stroke. By applying strategies that have been innovated for stroke rehabilitation, our preliminary results suggest that massed practice and somatosensory stimulation can improve hand/arm function in individuals with chronic incomplete tetraplegia. These improvements may be accompanied by improved cortical output and may also be associated with improvements in quality of life. The proposed studies focus on these outcomes. In Aim 1, we will quantify and compare changes in skilled hand/arm use, grip force and sensory function associated with either: massed practice training + somatosensory stimulation, somatosensory stimulation alone, or a control intervention (conventional resistance training). In Aim 2, we will quantify and compare changes in cortical neurophysiology associated with either: massed practice + somatosensory stimulation, somatosensory stimulation alone, or a control intervention. In Aim 3, we will quantify and compare changes in self-assessment of quality of life and societal participation associated with massed practice + somatosensory stimulation, somatosensory stimulation alone, or a control intervention. We believe the outcomes of the proposed studies will have a positive influence on function and quality of life for individuals with incomplete tetraplegia due to spinal cord injury. [unreadable] [unreadable] [unreadable] [unreadable]